In order to improve the device characteristics of semiconductor devices attempts have been made to reduce the final thickness of semiconductor material. In particular for power semiconductor devices, it is often desired that the semiconductor body of such devices has a thickness which is just sufficient for accommodating the device or circuit.
The manufacturing and handling of thin semiconductor chips and wafers is often complicated since the brittle semiconductor material such as silicon carbide (SiC), once thinned, is prone to breaking. Further, monocrystalline SiC is comparatively expensive. To improve the mechanical stability of thin semiconductor material, carrier systems have been developed. One approach uses a polycrystalline SiC (poly-SiC) carrier wafer attached to a monocrystalline SiC layer. This structure may be formed by direct bonding a monocrystalline SiC substrate to the carrier wafer and subsequent peeling the monocrystalline SiC substrate from the carrier wafer while leaving part of the single-crystal substrate on the carrier wafer. Although being cheaper than monocrystalline SiC, poly-SiC carrier wafers are still comparatively expensive. Further, the formed interface between poly-SiC and monocrystalline SiC requires special care. This increases processing costs.
For these and other reasons there is a need for the present invention.